Means for preventing surging in centrifugal compressors.



S. A. MOSS. MEANS FOR PREVENTING SURGHIG IN CENTRIFUGAL COMPRESSORS. APPLICATION TILED JAN.11,1918.

1 85,286, Patented J an. 27, 1914.

Witness 6 5: Im/enbor:

Sanforci Mo5s,

Hi5 k/ltzborne an enlargennuil of the intake pipe ilomf rules on the ineoming volume :ilul lJj' its inoremenlup and clown the RLll ol' the motor lo proper name or other s served by lhe machine.

l" delivery pipe 0 a bypass pipe z of lo the intake pipe. entering" it at heir en ihe flout and the rotor of 711323. bnial bypass pipe is eontmlled lie 0 :HljllSUril by hand lo give rhe l queu ng when the constant \oluiue i:- set for a. volume below low-al znpl tely (flosell for greuler .'olin or ler to adjust l'he constant \ulrniug ineehuuisru for rlill'erent onlmeans, sueh as the weights 9 is pro- "vi iuountml on lhe roo l0 volumes-tell i v i l mini lo the parts eonnevlell to v the routroillug uw-f'huuism of the lHUlUl [in uioiounuie iueelmnisui could also be usell.

lnusuuuli as the returned :lir enters the intulie above the iioul it does not inilnenve soul lion on?! so lloes not prevent the lntler l'roni continuing t perr'mni itsofiieo of properly regulating iihe speed of the motor. .ie the invention in another way, .ie volume of air which il is lerirleil u rh he furnace. and for which lume gorernor is set. if

volume. We l) .'}.m:-s o lhnl flu. volume of llliLLl urcuhues through the cointhan lihe break-flown 1' l- :ninnting pulsations which .'.ise occur. Taking a co n-role example, and supposing 5" volume is 12,000 cubic feel i i at normal speed and pressure musically. as do zrul ii. is clesired to supply 10,000 cubic fee i of air per unit of time. The constant volume governor will be set for 10,000 cubic feet by cl anging the weights or otherwise suitably adjusting tne mechanism and the bypass valve will be adjusted so as to bypass about 3PM) Pnoie feet of fluid. The compressor hen he aYOllilllg on a load of 1300i Feel. and will therefore Work above iln: --l'i J/Z1 poinL and the fin-nice will remire mil; 1 ),000 cubic feet of air. I have nimble place for connecting the unlit lo the disooazcge pipe of the v.--or,l;iul the invention is not limited 15 shown *npres l\ e oeing the of the air rolunin rluinges formed by the com'pr since said conduil; r 7 point in the discharge pipe somewhat remote from the o pressor if is; be c more convenien; so do so, for example in applying my invention to existing appsrat-us.

accordance wi patent statutes, If

she provisions of the .ve described the principle of operatic my HLVEDiLlOIl, together with the sppsrsu which I now consider to represent the best embodiment fihereof; but I desire to hoveit understood tlfet the appsratus shown is onl illustrative, and that "the invention can be carried out by other means,

Wlm I claim new and desire to secure by Letters oi the i) lied States is:- 1. In combination, a, centrifugal cornpressor which is subject to surging at light loads, a constant volunic governor therefor, and a bypass for returning fluid to the intake pipe at a point between she governor and compressor whereby the compressor is always loaded t e value above the breakdown point, and all oi the fluid entering the compressor acts on governor.

2. In combin, on, centrifugal cornprcsscr which suhj io surging at light loads, a constant volume fies-i3 governor therefor. and n bypass for returning fluid co the intake pipe at s oint above the float or" said governor whereby i-lie Work peressor is always maintained above the breakdown point.

3. In combination, a centrifugal coih- 'prcssor which is subject to surging at light loads, a constant volume governor, a bypass "for returning fluid so the intake pipe at a point between the go rnor and compressor, and means for regulating the flow through said bypass to pnevent the load on the corn pi'cssor from falling below the breakdown point. i

4. In combination, a centrifugal compressor which is subject 0 surging at light loads, an inlet and a discharge conduit therefor, a constenhvolurne governoriherefor l0- acted in the inlet, a bypass which is connect ed at one end to the discharge conduit and at the other end to; t11e inlet conduit at a point between said governor tho im peller of the compressor, and means for contr lling the effective discharge area, oft-he bypass.

5. The combination of a centrifugal compressor which is subject to surging at light loads, amotor for driving it, a governing mechanism therefor responsive to a change in condition of the fluid passing through the compressor, and aconduit Which at light losds returns a portion of the fluid discharged by the compressor foo a. point in its inlet; between the governing mechanism on the compressor to prevent surging.

6. The combination of a centrifugal compresscr which is subject to surging at light loads, an inlet and s discharge conduit therefor, a. motor for driving the compressor, a regulator for the motor, means responsive to s change in condition of the fiuidps'ssing through the compressor for adjusting the regulator, and a conduit that receives fluid of higher pressure from the discharge side of the compressor and returns it to the inlet at a point between said adjustin means and the compressor Where said fluid mixes with the fresh air and again passes through the compressor whereby a, minimum loadon the compressor is maintained irrespective of the demand for compressed fluid.

In W'lillSS whereof, l have hereunto set my hand this 9th day of onusry 1913.

SANFORD A. MOSS.

Witnesses:

JOHN A. McMAnus, JL, Hnifinr O. Wrrsrsnnonr. 

